JP3603074B2 - Safety control device for combustion equipment and combustion equipment - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a safety control device for a combustion device such as a gas water heater and a combustion device.
[0002]
[Prior art]
Recently, a gas water heater equipped with a CO sensor and a microcomputer that performs safety control based on the CO concentration signal from the CO sensor has been developed. More specifically, the microcomputer determines whether or not there is a danger to the human body based on the CO concentration, and when it is determined that there is a danger, stops the combustion and activates the alarm unit.
By the way, after the combustion stoppage as described above, the CO concentration in the room is reduced by natural ventilation, and accordingly, the degree of danger to the human body is reduced. Therefore, the combustion may be restarted in many cases. Accordingly, a safety control device has been developed in which when the operation switch is once turned off and then turned on again, combustion can be restarted and an alarm is stopped.
[0003]
[Problems to be solved by the invention]
However, when the CO concentration is extremely high, it may be too dangerous to restart the combustion control and display no warning when the operation switch is once turned off and then turned on again.
[0004]
[Means for Solving the Problems]
The invention according to claim 1 includes (a) a CO concentration detecting means, and (b) periodically integrating a numerical value based on the CO concentration detection information from the CO concentration combustion detecting means and attenuating the numerical value according to an elapsed time, A danger determining means for calculating a danger level and recognizing a danger level at which combustion should be stopped in a plurality of stages; and (c) stopping the combustion when the danger determination means determines that the danger level to stop the combustion is required. Combustion control means for enabling restart of combustion when it is determined that the risk is high, and for preventing combustion restart when it is determined that the risk is at a high level. The gist is the safety control device for combustion equipment.
According to a second aspect of the present invention, the safety control device for a combustion device according to the first aspect further includes a clear switch, and the combustion control means is in a state where the combustion cannot be restarted when a cancel signal is received from the clear switch. Is canceled.
According to a third aspect of the present invention, in the safety control device for a combustion apparatus according to the first aspect, the combustion control means restarts the combustion after a lapse of a predetermined time after stopping the combustion by determining that the risk is at a high level. The disabling state is released.
According to a fourth aspect of the present invention, there is provided the safety device for a combustion apparatus according to any one of the first to third aspects, further comprising a warning unit, and the warning unit determines that the danger determining unit determines that the danger level should stop the combustion. It is characterized in that the mode of the alarm is different depending on whether it is activated at a low level and when it is determined to be a high level.
According to a fifth aspect of the present invention, in the safety control device for a combustion device according to any one of the first to fourth aspects, the danger determining means determines the lowest level of danger to be the level at which combustion should be stopped. When the next stage of high danger is recognized, the fact that this is the lowest danger is determined, and the combustion is stopped, the fact of this combustion stop is stored, and the combustion is restarted in a state where the fact of this combustion stop is stored. Is characterized in that the combustion is stopped when the next higher risk is recognized.
[0005]
According to a sixth aspect of the present invention, there is provided (a) a burner, (b) a CO concentration detecting means, and (c) periodically integrating a numerical value based on the CO concentration detection information from the CO concentration detecting means and according to the elapsed time. A danger calculating means for calculating the degree of danger and recognizing the danger to be stopped in a plurality of stages; and (d) the burner when the danger is determined to be the danger to stop the combustion. Combustion control means for stopping the combustion of the fuel, and enabling the restart of combustion when it is determined that the danger is at a low stage, and disabling the restart of combustion when it is determined that the danger is at a high stage. The gist of the present invention is a combustion device characterized by being provided.
According to a seventh aspect of the present invention, there is provided the combustion apparatus according to the sixth aspect, further comprising a clear switch, wherein the combustion control means cancels the non-restartable state when receiving a cancel signal from the clear switch. It is characterized by.
According to an eighth aspect of the present invention, in the combustion apparatus according to the sixth or seventh aspect, the danger determining means includes a plurality of the lowest level danger and the next highest level danger as the low level dangers to stop the combustion. Recognizing the stage, determining that this is the lowest degree of risk, and stopping the combustion when stopping the combustion, storing the fact of the combustion stop, and restarting the combustion in the state where the fact of the combustion stop is stored, The combustion is stopped when a high risk is recognized.
[0006]
[Action]
According to the first and sixth aspects of the present invention, the danger determining means determines whether or not there is danger based on the CO concentration detection information from the CO concentration detecting means , and recognizes the risk of stopping combustion in a plurality of stages. The combustion control means stops the combustion when the danger determination means determines that the degree of danger should be stopped. When it is determined that the risk is at a low level, the combustion can be restarted, and when it is determined that the risk is at a high level, the combustion cannot be restarted. As described above, after the risk determination at the low stage, the reduction of the risk to the human body during the elapsed time from the stop to the restart of combustion is expected.
On the other hand, after the high-level risk determination, the combustion is not restarted, and the safety of the user is further ensured.
[0007]
According to the second and seventh aspects of the present invention, when the maintenance / repair operator operates the clear switch and outputs the cancel signal, the combustion control means enables the restart of combustion.
[0008]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a gas water heater (combustion device). In this gas water heater, a burner 11 is disposed substantially at the center in the casing 10. The burner 11 is supplied with gas through a gas pipe 12 and a gas nozzle (not shown), and is supplied with air sent by a fan 13. These gases and air are mixed in the burner 11, and this mixed gas is blown out from the upper surface of the burner 11. This mixed gas is ignited by discharging an igniter (not shown). The gas pipe 12 is provided with an electromagnetic valve 14 for controlling gas supply. The ignition is confirmed by the flame rod (flame detection sensor) current. This flame rod current is also used to determine whether the flame is lifted.
[0009]
Above the burner 11, a heat exchanger 15 heated by the flame from the burner 11 is arranged. A water supply pipe 16 passes through the heat exchanger 15, and a water tap 17 is provided at a tip of the water supply pipe 16. Therefore, when the tap 17 is opened, hot water from the heat exchanger 15 comes out. The water supply pipe 16 is provided with a flow sensor 18 so that the flow of water when the tap 17 is opened can be detected.
[0010]
An exhaust port 10a is provided at an upper portion of the casing 10, and the combustion exhaust gas is discharged outside through a chimney 19 connected to the exhaust port 10a. A CO sensor 20 (CO concentration detecting means, incomplete combustion detecting means, abnormality detecting means) is provided near the exhaust port 10a, and outputs a signal indicating the CO concentration of the exhaust gas. A signal from the CO sensor 20 is sent to a control unit 30 provided in the casing. The control unit 30 includes a microcomputer 31 for processing a signal from the CO sensor 20, an interface thereof, a clear switch 32, and the like. The clear switch 32 can be turned on only when a maintenance / repair worker removes the casing 10 and removes the housing of the control unit 30, and the user cannot easily operate the clear switch 32.
[0011]
An operation panel 40 installed on the outer surface of the casing 10 is connected to the control unit 30. The operation panel 40 includes a liquid crystal display unit 41, an operation switch 42, a lamp 43, a buzzer 44, and the like. The liquid crystal display section 41 normally displays the set temperature. As will be described later, when the degree of danger due to CO gas increases, the liquid crystal display unit 41 switches to an alarm display, the lamp 43 flashes, and the buzzer 44 outputs an alarm sound. Thus, the liquid crystal display 41, the lamp 43, and the buzzer 44 are provided as alarm means.
[0012]
The microcomputer 31 executes a combustion and alarm control program shown in FIG. Before describing this program, the basic principle of combustion control will be described. The microcomputer 31 assumes that the combustion exhaust gas leaks from the casing 10 and the chimney 19 into the room, and based on the CO concentration from the CO sensor 20, the blood hemoglobin CO concentration of the human body (based on the total hemoglobin number in the blood). The percentage of hemoglobin bound to CO) is estimated. Then, the degree of danger to the human body is determined based on the blood hemoglobin CO concentration.
[0013]
More specifically, the CO in the exhaust gas is sucked in with the breathing action of a person and combines with the hemoglobin in the blood. Since hemoglobin bound to CO accumulates in blood, the blood hemoglobin CO concentration increases as the CO concentration in the exhaust gas increases and as the elapsed time increases. Therefore, the microcomputer 31 obtains the blood hemoglobin CO concentration by integrating the value obtained by multiplying the CO concentration in the exhaust gas, which is periodically detected, by the absorption rate into the human body at this CO concentration. However, when the CO concentration is zero or low, the blood hemoglobin CO concentration attenuates with the passage of time. Therefore, the blood hemoglobin CO concentration is calculated taking this attenuation into account. Then, a ratio TR between the calculated blood hemoglobin CO concentration and the lowest concentration (hazard reference concentration, for example, 25%) that adversely affects the human body is determined. In this embodiment, the ratio TR is treated as the risk.
[0014]
Each time the CO concentration is detected, a time T at which the blood hemoglobin CO concentration will reach the above-mentioned dangerous reference concentration, assuming that the detected CO concentration is maintained as it is, is obtained from the map. By dividing the period t to obtain t / T, and integrating the t / T, the degree of risk TR may be obtained.
[0015]
In this embodiment, at first, the risk TR is regarded as 0.7 or more as a danger, and control such as stop of combustion and warning is performed. However, the case where the risk TR is 0.7 or more and less than 1.0 is defined as a low-level risk, and the case where the risk TR is 1.0 or more is defined as a high-level risk. Performs corresponding combustion control and alarm control.
[0016]
The flags and registers used in the control program of FIG. 2 will be described. The flag A indicates the fact that the risk TR is determined to be in the low level while the risk TR is determined to be in the low level, and the flag B indicates the fact that the risk TR is determined to be in the high level. The register X indicates the fact that it is determined that the degree of risk TR is 0.7 or more and less than 0.8 when “1”, and that the degree of risk TR is 0.8 or more and less than 0.9 when “2”. It represents the fact that it is determined that there is, and the fact that it is determined that the degree of risk TR is 0.9 or more and less than 1.0 when “3”.
[0017]
Next, the control program will be described in detail with reference to FIG. This control program is started by power-on (plugging the power plug of the gas water heater into an outlet). First, initialization is performed except for the register X and the flag B (step 101). The meaning of this initialization will be described later. Next, it is determined whether the flag B is set (step 102). Normally, a negative determination is made here and the routine proceeds to step 103. In step 103, it is determined whether or not the operation switch 42 has been turned on. When a negative determination is made, the flag A is cleared in step 104, the alarm is stopped, and the process returns to step 103 again. The meaning of step 104 will be described later. When an affirmative determination is made in step 103, it is determined whether or not the tap 17 has been opened based on a signal from the flow sensor 18 (step 105). If a negative determination is made, step 104 is executed and the process returns to step 103. As described above, until the operation switch 42 is turned on by the user and the tap 17 is opened, the combustion control is not started, and the combustion is ready.
[0018]
When the user turns on the operation switch 42 and opens the tap 17, a positive determination is made in steps 103 and 105, so that the process exits the loop and proceeds to step 106. In step 106, it is determined whether the flag A has been set. Usually, a negative determination is made here and the process proceeds to the start of combustion. That is, the fan 13 is rotated and the electromagnetic valve 14 is turned on to start gas supply (step 107), discharge the igniter to ignite, and supply a desired gas when the flame rod current is detected (step 108). .
[0019]
Next, the CO concentration is detected based on the signal from the CO sensor 20, and the above-mentioned risk TR is calculated (step 109). Next, it is determined whether or not the register X is "0" (step 110). Normally, the value of the register X is “0”, so an affirmative determination is made here, and the routine proceeds to step 111. In step 111, it is determined whether or not the degree of risk TR is less than 0.7. Normally, the risk is less than 0.7, so an affirmative determination is made here, and the routine proceeds to step 112. At step 112, it is determined whether or not the tap 17 is open. If a positive determination is made, the process returns to step 109. As described above, when the combustion is being performed under the condition that almost no CO gas is generated, the loop of steps 109 to 112 is repeatedly executed while the tap 17 is opened, and the combustion is performed. To be continued. In step 109, time management is performed so that the CO detection and the risk TR calculation are performed periodically (for example, every 10 seconds) only once per loop.
[0020]
If the tap 17 is closed during the combustion control, a negative determination is made in step 112, and the process proceeds to step 113, where the electromagnetic valve 14 is turned off to stop gas supply. That is, the combustion is stopped. Thereafter, the process returns to step 103, and enters the above-described combustion preparation state.
[0021]
When incomplete combustion occurs, the CO concentration in the exhaust gas increases, and the risk TR increases with time and may reach 0.7. In this case, a negative determination is made in step 117, and the process proceeds to step 114, where it is determined whether the risk TR is less than 0.8. If the CO concentration is not very high and the degree of risk TR, which is an integrated value thereof, rises relatively slowly, a negative determination is made here and the routine proceeds to step 115. At step 115, the register X is set to "1". At the next step 116, an alarm is executed and the flag A is set. Then, the process proceeds to the next step 113 to stop the gas supply. As described above, when the danger level reaches the predetermined level of 0.7 or more but reaches a low-level danger level, a warning and a stop of combustion are executed to ensure the safety of the user. The mode of the alarm is as described above. In addition to the blinking of the lamp 43 and the output of the buzzer sound from the buzzer 44, the display unit 41 displays that the low-level danger level has been reached by a code or a character. Thereafter, the process returns to step 103.
[0022]
Immediately after the low-level danger is detected as described above, the operation switch 42 remains on and the tap 17 remains open, so that the affirmative determination is made in steps 103 and 105, and the process proceeds to step 106. Here again, since the flag A has been set, an affirmative decision is made and the routine returns to step 103. Therefore, steps 103, 105, and 106 are repeatedly executed, and the alarm display is continued.
[0023]
In the situation described above, if the user notices the alarm and turns off the operation switch 42, a negative determination is made in step 103, and the process proceeds to step 104, where the flag A is cleared and the alarm is stopped. Thereafter, steps 103 and 104 are repeatedly executed, and the same combustion preparation state as described above is obtained. In the present embodiment, even if the operation switch 42 remains ON, when the tap 17 is closed, a negative determination is made in step 105, so that step 104 can be executed, and thereafter, steps 103, 105, and 104 are repeatedly executed. It is ready for combustion. However, generally, the user should perform both the operation of turning off the operation switch 42 and the operation of closing the tap 17 after the alarm.
[0024]
After the alarm, when the user turns on the operation switch 42 again and opens the hot water tap 17 again, an affirmative determination is made in steps 103 and 105 and the process proceeds to step 106, where a negative determination is made because the flag A has already been cleared. Then, the ignition operation (steps 107 and 108) is executed to detect the CO concentration and calculate the degree of risk TR (step 109). Next, it is determined whether or not the register X is "0" (step 110). As described above, in the combustion after the register X is set to "1", a negative determination is made here, and further, an affirmative determination is made in step 117, and the routine proceeds to step 118. In step 118, it is determined whether or not the degree of risk TR is less than 0.8. If the incomplete combustion has not occurred, the degree of risk TR has not increased, so an affirmative determination is made here and the routine proceeds to step 112, where it is determined whether or not the tap 17 is open. It returns to step 109. Thus, after the risk TR is determined to be 0.7 or more and less than 0.8 (low-level risk) and the register X becomes “1”, the operation switch 42 is turned on and the hot water tap 17 is turned on. In response to the opening, combustion can be resumed without an alarm, and combustion is continued by repeatedly executing steps 109, 110, 117, 118, and 112 in order until the degree of risk TR becomes 0.8 or more. be able to.
[0025]
When the incomplete combustion occurs again after the restart of combustion in the state where the register X is "1" and the risk TR becomes 0.8 or more, a negative determination is made in step 118 and the routine proceeds to step 119, where the risk TR Is less than 0.9. If the degree of risk TR rises gently, an affirmative determination is made here, the register X is set to "2" in step 120, the alarm and the flag A are set (step 116), and the gas supply is stopped as described above. After executing (Step 113), the process returns to Step 103. The restart of combustion when the register X is "2" is the same as that when the register X is "1", and therefore the description is omitted.
[0026]
When resuming combustion in the state where the register X is "2", a negative determination is made in steps 110 and 117, so the process proceeds to step 121, and an affirmative determination is made here, and the process proceeds to step 122 to set the risk degree TR to 0.9. Is determined. When the incomplete combustion has not occurred, the degree of risk TR has not increased, so that an affirmative determination is made here, and the routine proceeds to step 112. As described above, by repeating steps 109, 110, 117, 121, 122, and 112 in order, combustion can be continued.
[0027]
If the incomplete combustion occurs again after the restart of combustion in the state where the register X is "2" and the risk TR becomes 0.9 or more, a negative determination is made in step 122 and the routine proceeds to step 123 where the risk TR Is less than 1.0. If the degree of risk TR rises gently, an affirmative determination is made here, the register X is set to "3" in step 124, the alarm and the flag A are set (step 116), and the gas supply is stopped as described above. After executing (Step 113), the process returns to Step 103. Since the restart of combustion when the register X is "3" is the same as that when the register X is "1", the description is omitted.
[0028]
When restarting combustion with the register X being "3", a negative determination is made in steps 110, 117, and 121, so the process proceeds to step 125, where it is determined whether the risk TR is less than 1.0. You. When the incomplete combustion has not occurred, the degree of risk TR has not increased, so that an affirmative determination is made here, and the routine proceeds to step 112. As described above, by repeating steps 109, 110, 117, 121, 125, and 112 in order, combustion can be continued.
[0029]
Next, a case where it is determined that the degree of risk is high is described. When the incomplete combustion occurs again and the degree of risk TR becomes 1.0 or more after the restart of combustion in the state where the register X is "3", a negative determination is made in step 125 and the gas supply is stopped (step 126). , The timer is started, the register X is set to "0", and the flag B is set (step 127). If the degree of danger TR suddenly increases, even if combustion is being performed in any state of the register X of “0”, “1”, or “2”, steps 114, 119, and 123 are executed. If the determination is negative, the process can proceed to step 126.
[0030]
In step 130, it is determined whether or not the operation switch 42 is on. Immediately after a negative determination is made by the switches 123 and 125, since the operation switch 42 is in the ON state, an affirmative determination is made and an alarm is executed (step 131). The mode of the alarm is different from the case of the low-level danger level. That is, the blinking cycle of the lamp 43 is increased, the buzzer sound from the buzzer 44 is increased or increased, and the display unit 41 displays that the high degree of risk has been reached by a code or a character. If the user notices this warning and turns off the operation switch 42, a negative determination is made in step 130 and the process proceeds to step 132 to stop the warning. Therefore, the user is not frustrated by the continuation of this alert. After step 131 (or 132), it is determined whether or not the clear switch 32 has been turned on (step 133). If a negative determination is made here, it is determined whether or not a predetermined time, for example, 4 hours, has elapsed (step 134). If a negative determination is made here, the process returns to step 130. Until a worker called by the user for repair turns on the clear switch 32 or until four hours have elapsed, even if the operation switch 42 is turned off and on again, the loop cannot be exited, The combustion stop state is not released. In addition, since the alarm is executed when the operation switch 42 is turned on again, the user can recognize that the combustion stop state is not released due to danger.
[0031]
As described above, when it is determined that the risk is at a high level, the restart of combustion is more strictly regulated and an alarm is issued as compared with when the risk is determined at a low level, so that the safety of the user can be ensured.
When the clear switch 32 is turned on or when a predetermined time has elapsed, an affirmative determination is made in step 133 or step 134, and the process exits the loop and proceeds to step 135. Return. As a result, the state returns to the normal combustion preparation state.
[0032]
When the user unplugs the power plug, the microcomputer 31 stops the combustion and alarm control. However, since the microcomputer 31 is supplied with power from the backup power supply, the values of the flags and the registers are retained. When the user plugs in the power plug again and the microcomputer restarts the program of FIG. 2, initialization is performed in step 101, but the register X and the flag B are not initialized. Then, in the next step 102, it is determined whether or not the flag B is 1. If the combustion has been stopped by the high-level risk determination, an affirmative determination is made here and the routine proceeds to step 130. Therefore, when the power is turned off and on, the combustion stop state cannot be released in the same manner as when the operation switch 42 is turned off and on.
[0033]
The present invention is not limited to the above embodiments, and various modes are possible. For example, in the above embodiment, the alarm means includes the display unit 41, the lamp 43, and the buzzer 44, but only one of them may be used.
When judging the degree of danger at a high level, an alarm may be issued regardless of whether the operation switch is on or off. When the operation switch is on, an alarm is issued by the display unit 41, the lamp 43, and the buzzer 44. Alternatively, an alarm may be issued only on the display unit 41 when the operation switch is turned off.
In the specification of the present application, "ON" of the operation switch means that the operation switch itself is maintained in an ON state, a state in which the operation switch ON signal is held by a flip-flop, or a microcomputer. It may mean a state in which a signal is stored .
The present invention can be applied not only to gas-fired equipment but also to combustion equipment using other fuels such as petroleum.
[0034]
【The invention's effect】
As described above, according to the first and sixth aspects of the present invention, the combustion can be restarted at the time of the low-level danger determination, and the combustion cannot be restarted at the time of the high-level danger determination. It can be more reliable. According to the second and seventh aspects of the present invention, combustion can be restarted when a maintenance / repair operator operates the clear switch.
[Brief description of the drawings]
FIG. 1 is a schematic view of a water heater according to one embodiment of the present invention.
FIG. 2 is a flowchart showing a combustion control and display control program executed by the microcomputer of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Operation switch 2 ... Abnormality detection means 3 ... Danger judgment means 4 ... Cancellation means 5 ... Combustion control means 6 ... Warning means 7 ... Warning control means 20 ... CO sensor (CO concentration detection means, incomplete combustion detection means, abnormality detection means)
31 ... microcomputer 32 ... clear switch (cancellation means)
41, 43, 44 ... alarm means 42 ... operation switch

Claims (8)

(B) CO concentration detecting means;
(B) The numerical value based on the CO concentration detection information from the CO concentration detecting means is periodically integrated and attenuated according to the elapsed time to calculate the danger, and recognize the danger to be stopped in a plurality of stages. Means to judge danger
(C) When the danger determining means determines that the danger should be stopped, the combustion is stopped. When it is determined that the danger is at a low level, the combustion can be restarted. A combustion control unit that, when determined, disables combustion restart;
A safety control device for combustion equipment, comprising: 2. The safety control device for a combustion apparatus according to claim 1, further comprising a clear switch, wherein the combustion control means cancels the combustion non-restartable state when receiving a cancel signal from the clear switch. 2. The safety control of a combustion device according to claim 1, wherein the combustion control means cancels the combustion resumable state after a lapse of a predetermined time after stopping the combustion by judging that the degree of danger is at a high level. apparatus. Further, an alarm means is provided. The alarm means is activated when the danger determining means determines that the danger is to stop the combustion. The safety device for a combustion device according to any one of claims 1 to 3, wherein the warning mode is different between the safety devices. The danger determining means recognizes a plurality of levels of the lowest level and the next highest level as the low level levels of danger at which the combustion should be stopped, and determines the lowest level to stop the combustion. 2. The method according to claim 1, further comprising storing the fact that the combustion has been stopped, and restarting the combustion with the fact that the combustion has been stopped stored when the next higher risk is recognized. The safety control device for a combustion device according to any one of claims 1 to 4. (A) Burner,
(B) CO concentration detecting means;
(C) Numerical values based on the CO concentration detection information from the CO concentration detecting means are periodically integrated and attenuated in accordance with the elapsed time to calculate the risk level, and recognize the risk level at which combustion should be stopped in a plurality of stages. Means to judge danger
(D) When the danger determining means determines that the danger level should be stopped, the burner stops the combustion. When the danger level is determined to be low, the combustion can be restarted. Combustion control means that disables combustion restart when it is determined that the risk is
A combustion device comprising: 7. The combustion apparatus according to claim 6, further comprising a clear switch, wherein the combustion control means cancels the non-restartable state when receiving a cancel signal from the clear switch. The danger determining means recognizes a plurality of levels of the lowest level and the next highest level as the low level levels of danger at which the combustion should be stopped, and determines the lowest level to stop the combustion. 7. The method according to claim 6, wherein the fact that the combustion is stopped is sometimes stored, and when the combustion is restarted in a state where the fact of the combustion stop is stored, the combustion is stopped when the next higher risk is recognized. Or the combustion apparatus according to 7.

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